package com.yuntian.config;

import org.apache.shiro.web.servlet.ShiroHttpServletRequest;
import org.apache.shiro.web.session.mgt.DefaultWebSessionManager;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.util.StringUtils;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import java.io.Serializable;

/**
 * <p>自定义sessionID获取</p>
 * 传统结构项目中，shiro从cookie中读取sessionId以此来维持会话，在前后端分离的项目中（也可在移动APP项目使用），
 *      我们选择在ajax的请求头中传递sessionId，因此需要重写shiro获取sessionId的方式。
 * 2019/3/8/0008 14:26
 *
 * @author lvjie
 */
public class MySessionManager extends DefaultWebSessionManager {
    private static final String TOKEN = "token";
    private static final String REFERENCED_SESSION_ID_SOURCE = "Stateless request";
    public MySessionManager(){
        super();
    }

    @Override
    protected Serializable getSessionId(ServletRequest request, ServletResponse response) {
        String id = WebUtils.toHttp(request).getHeader(TOKEN);
        //如果请求头中有 token 则其值为sessionId
        if(!StringUtils.isEmpty(id)){
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID_SOURCE,REFERENCED_SESSION_ID_SOURCE);
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID,id);
            request.setAttribute(ShiroHttpServletRequest.REFERENCED_SESSION_ID_IS_VALID,Boolean.TRUE);
            return id;
        }else{
            //否则按默认规则从cookie取sessionId
            return super.getSessionId(request,response);
        }
    }
}
